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• ### Wave

a disturbance passing through a medium or space

### Medium

substance that the wave is passing through

### Mechanical Waves

require a medium to travel through (water and sound waves)

### Electromagnetic Waves

do not require a medium (light and radio waves)

### Transverse Waves

particles on the wave vibrate perpindicular to the direction that the wave is going

### Longitudinal Waves

particals on these waves vibrate parallel to the direction that the wave is moving

### Wavelength

the distance from a point on one wave to the identical point on the next wave

### Frequency

number of waves passing each second, measured in hertz

### Amplitude

maximum displacement of a wave from the rest position or the size of the wave or how large the wave is

### Reflection

waves will bounce off barriers at an angle equal to the angle they will strike the barrier

### Law of Reflection

"Angle of incidence= Angle of reflection"

### Refraction

bending of a wave as it passes at an angle into another medium

### Diffraction

bending of waves around barriers

### Damping

dissipation of wave energy as the wave moves away from the source

### Impedance

how easily or difficultly a wave can be launched in a medium

### Interference

the effect of 2 waves passing each other as described by the principle of Superposition

### Principle of Superposition

when 2 waves pass each other, the resulting wave is the vector of the 2 waves. After they meet, they continue undisturbed

### Destructive Interference

the waves partly or completely cancel as they pass

### Rectilinear propagation

wave swill travel in straight lines or paths in a uniform medium

### Explain behavior of waves at different boundaries

when a wave strikes a rigid barrier, it reflects inverted. When it strikes a non-reigid barrier, it reflects upright

### Sonic Spectrum

complete range of the longitudinal waves

### Audio Spectrum

part of the sonic spectrum that humans can hear frequencies between 20Hz and 20,000Hz

### Infra Sonic

range of frequencies below 20Hz

### Ultra Sonic

range of frequencies above 20,000 Hz. Many animals can hear thes frequencies

### Echo Location

animals like bats send out ultrasonic frequencies and "hear" the reflection to determine if an object is near

### Loudness

subjective perception of intensity

### Intensity

power of the sound wave passing through an area

### Relative Intensity

compares the intensity to the softest sound or "threshhold of hearing"

### Pitch

subjective perception of frequency

### Doppler Effect

change in frequency heard when the source of sound and the person recieving the sound are in relative motion

### Fundamental frequency

harmonics are the whole number multiples of this

### Harmonics

whole number multiples of the fundamental frequency

### Quality of Sound

depends upon the number of harmonics produced and their intensities

### Law of Strings

for the frequency produced by a vibrating string: the frequency is directly proportional to the tension and the frequency is inversely proportional to the string's density, diameter, and length

### Sympathetic Vibrations

occurs when a standing sound wave is produced in a tube causing the tube to produce an amplified sound

### Beat

2 sound waves close in frequency prducing an oscillating sound wave

### Node

wave undergoes no displacement

### Antinode

wave undergoes maximum displacement

### Threshold of Pain

120 dB over a long period of time

### Threshold of Hearing

decibel scale, can also be called relative intensity

### How is sound produced and transmitted?

sound is produced by vibration, a vibrating object will send out a wave, the faster the object vibrates, the higher the frequency

### Compare the velocity of sound in solids, liquids, gases and space.

sound travels fastest in solids, slower in liquids, slowest in gases and it doesn't travel at all in space

### Explain how the ear detects sound.

sound travels down the auditory canal and strikes the eardrum. The vibrating eardrum causes 3 tiny bones on the other side of the eardrum to vibrate, they send pulses through the cochlea which is lined with cilia. The movement of cilia is detected as sound.

### Standing wave

interference pattern produced when 2 waves of the same frequency and wavelength pass each other

Example: